Why ST37 / Q235 Is Widely Used for Pipe Fittings
Due to its low carbon content and stable mechanical properties, ST37 (Q235) steel is widely used in the manufacturing of threaded pipe fittings. This material offers good machinability, reliable strength, and excellent cost efficiency, making it especially suitable for CNC turning production.
For standard pressure applications, ST37/Q235 fittings provide sufficient strength while keeping material and processing costs under control. This is why many OEM and ODM customers choose ST37/Q235 as an economical alternative to higher-grade carbon steel.
ST37 Pipe Fittings Manufacturing Process
At Yuhuan Hongqian, ST37 and Q235 pipe fittings are mainly produced by CNC turning machines to ensure high dimensional accuracy and thread consistency. With over 80 sets of CNC lathes, we are able to handle both small-batch customized orders and large-volume production efficiently.
Each steel fitting goes through strict process control, including raw material inspection, CNC machining, thread gauging, surface treatment, and final quality inspection before shipment.
What is ST 37?
ST37 is a German standard steel grade. ST37-2 corresponds to the Chinese carbon structural steel grade Q235B (the old designation was A3-B), and is mainly used in construction, underground engineering, and other fields. St 37 is a good material suitable produce for pipe ftitngs .
Comparison table for carbon steel structural grades
Are ST37 and Q235 Equivalent?
No , they are simiar but in reality they are widely considered equivalent in practical applications.
ST37 is a German standard structural steel grade (DIN 17100), while Q235 is a Chinese carbon structural steel grade (GB/T 700). Both steels have similar low carbon content, tensile strength, and mechanical performance, it is a very common material cnc turning for pipe fittings.
ST37 Steel Chemical Composition Table
| Element | Content Range (%) |
|---|---|
| C (Carbon) | 0.17 – 0.20 |
| Si (Silicon) | ≤ 0.40 |
| Mn (Manganese) | 0.35 – 0.65 |
| P (Phosphorus) | ≤ 0.045 |
| S (Sulfur) | ≤ 0.045 |
Chemical Composition of Q235 Steel
| Element | Content Range (%) |
|---|---|
| C (Carbon) | ≤ 0.22 |
| Si (Silicon) | ≤ 0.35 |
| Mn (Manganese) | 0.30 – 0.65 |
| P (Phosphorus) | ≤ 0.045 |
| S (Sulfur) | ≤ 0.045 |
Mechanical Properties of Q235 Steel
| Property | Value |
|---|---|
| Yield Strength (σy) | 235 MPa |
| Tensile Strength (σu) | 370 – 500 MPa |
| Elongation (A) | ≥ 20% |
| Hardness | 120 – 180 HB |
Surface Treatment Options for Carbon Steel Pipe Fittings
For ST37 pipe fitting , there are many types of the surface treatment .Such as Blackening, electrophoresis, galvanizing, Dacromet coating, nickel plated etc.
Also ST37 is a perfect material for welding . So only rust by oil is also a good option .
Typical Applications of ST37 Pipe Fittings
ST37 and Q235 is a common material , that is suitable produce for threaded pipe fittings , they are widely used in:
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Hydraulic systems
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Automotive and agricultural machinery
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HVAC and refrigeration systems
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Gas and fluid transmission pipelines
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General industrial equipment
For non-critical high-pressure systems, these carbon steel pipe fittings offer a reliable and economical solution.
Why Choose Yuhuan Hongqian
Yuhuan hongqian is a profeesional china cnc turning parts factory , with more than 8 years of experience in cnc machining and pipe fittings manufacturing. We are focus on supply OEM /ODM cnc turning parts ,especially in various type of pipe fitting, hydraulic fitting, hose fittings . We familiar with different type steel material , ST37 is just one of our familar and common material . we clear know about different way to reduce cost , such as bar , tube , cold head , hot forging to get suitable blank , give the best way to design your product with economy price .
How to place order ?
Our factory is keep supply non-standard drawings . So it different with standard parts factory , you can get goods always . standard goods always have stock when you need .
But for custom pipe fitting area , when you want to custom your metal parts . It will takes a long time .Usually it needs follow steps to custom made cnc turning parts：
1- Consult /Enquiry : Send us 2D/3D drawing ,we need study material , technical demand ,surface treatment , heat treatment , roughness demand .
Check if our equipment satisfy the drawing demand .
2-Quantity : Based on the quantity detail , we will check which blank suitable for the steel fittings .
2000pcs suitable for buying bars , 5000pcs quantity suitable custom tube /hot forging metal parts . 50000pcs may choose cold heading based on pipe fititng design .
Differnt quantity decide different blank .
3- Price : When we get all detail , we will quote the price for pipe fitting customers .
4-Samples : Approved price then need start produce a sample , customer need check the quality ,for factory need study the customer quality demand from the samples .
Samples is one of the important step to avoid the risk of batch prodcution and decide if you can catch the order from pipe fittings customer .It is necessary to inspection sample and study all detail for material inspection , size inspetcion ,surface inspection etc.
5-Final : It need a long time to wait and reply from customer . Usually it is big possibility when the samples approved , will have a small batch order to start cooperation .
Faq ：
1-Are you a factory or trade company ?
We are the china factory , professional supply various types of pipe fittings by steel and stainless steel. We are familar with St37 pipe fitting more than 8 years .
2-What is your production capacity?
We have more than 80 sets cnc lathe machines, drill machine , punch machine etc .
3-Which material you are good at ?
We are good at 1020,1008,1015,1035,1045, st37/Q235, 42crmo , 40cr ,12L14 etc.
Stainless steel include 201,303,304,316.
